Method of extracting platinum and other metals from their ores



I I S. S. SADTLERQ METHOD OF EXTRACTING PLATINUM AND OTHER METALS FROM THEIR ORES.

APPLICATION FILED DEC-3, I916.

1,353,248, Patented Nov. 9, 1920.

UNITED STATES Par-stir urrent SAMUEL S. SADTLER, OF MONTGOMERY COUNTY, PENNSYLVANIA.

METHOD OF EXTBACTING PLATINUM AND OTHER METALS FROM THEE ORES.

Specification of Letters Patent.

Patented Nov. a, 1920.

Application filed December 8, 1916. Serial Ito. mama T 0 all whom it may concern Be it known that I, SAMUEL S. SADTLER, a citizen of the United States, residing 1n Montgomery county, State of Pennsylvania,

have invented certain newand useful Improvements in Methods of Extractin Platinum and other Metals From Their res, of which the following is a specification.

Broadly considered, the object of my invention is to provide an improvement inbeing situated within or in contact with an electrolyte containing ions of an alkali metal, such as sodium, in strong solution;

The solution may be practically saturated, although I secure good results by the employment of a five per cent. solution and from that on up to saturation. The anode may consist of any suitable material or substance. I

Also in practising or carrying out the method embodying my invention the alkali metal ions in solution in the electrolyte should be in suflicicnt concentration to retard to the required extent the reaction with water of the alkali present in the amalgam to form a hydroxid and hydrogen. The presence of alkali metal ions in the electrolyte identical with those in the amalgam tends to and does protect the latter; that is to say, theamalgam is maintained in a substantially constant condition of strength and eificiency.

Preferably, I employ in the practising of my invention sodium as the alkali'metal. Theoretically and, as I have found, practically a hydroxid of the identical alkali metal is best to be employed in solution in the electrolyte, but as very strong solutions or" these metals with other ions or radicals also have a protective influence upon the amalgam I include them also as within my invention.

F or the purpose of enabling a better understanding of my invention and for purposes of description, but not of limitation of my invention, 1 shall explain and describe the same in connection with the apparatus illustrated in central vertical section in the accompanying drawing.

In the said drawing, 1 designates a tank or receptacle adapted to contain an electrolyte comprising in concentrated solution the salt of an alkali metal, such as sodium, or a hydroxid of the same, such as sodium hydroxid, and also comprising the ore in a finely divided or comminuted state and from which the metal, such as platinum, is to be extracted and separated. The sides of the tank or receptacle at their lower ends or edges are contracted as indicated at 2 and are provided with or terminate in a reduced neck-like portion 3 closed by means of a removable bottom 4. In the chamber or space formed by the reduced neck-like portion 3 mercury 5 is located, the top surface of which is in contact with the electrolyte. The mercury or the amalgam formed may be withdrawn through the pipe 6.

A pipe 7 is provided for drawing 0% from the bottom of the electrolyte adjacent to the top surface of the mercury 5 the electrolyte and the metal which may have been deposited upon the top surface of the said a agitator 10 is secured is supported in a bearing 15 formed in the cover 16 for the top oi: the tank or receptacle 1. The upper end of the said shaft is provided with a beveled gear 17 in engagement with and driven by a beveled gear 18 upon a shaft-.19 driven in any suitable manner. The shaft 19 is supported in bearings 20 in the upper ends of posts or standards upon the lid 16. 21 designates a funnel like projection formed upon the cover 16 and through which the tank or receptacle 1 may be charged. The tubular the anodes 24 are supported, said anodes being supported and insulated from the arms 23 by means of sleeves 25 of insulating material. The electric current is conducted to the said anodes 24 through a conducting wire 27 and is conducted from said anodes by the electrolyte within the tank or receptacle 1 to the mercury 5 and thence out through the conducting wire at 28.

By the means shown (although any other preferred means may be'employed) I am enabled to cause the electrolyte comprising the compound of the alkali metals, such as sodium, in concentrated solution and the ore which may be in solution therein to move or flow repeatedly and successively against or in contact with and along the surface of the mercury or amalgam 5, constituting the cathode of the electric circuit.

In the operation of the method the cur rent used should be and is sufficient to pro- (luce or effect the formation of an amalgam of the alkali metal and mercury which is rich in such metal. As already stated, the electrolyte containing the alkali metal ions in strong or concentrated solution has a protective influence upon the amalgam so formed so that it persists and is efficient for a considerable time even after the electric current is no longer flowing.

I desire to point out that my invention may be carried out in two ways. In one of these ways the amalgam is made or produced from a solution containing alkali metal (such as sodium) ions, and in the other of which the ore pulp in a strong solution containing the same alkali metal ions is agitated or run over a previously formed amalgam or in any desired way brought into repeated and successive contact with it. I

have found in actual practice that the mercury amalgam is active after the current is cut pit and that the amalgam will attract platinum for about as long a time as it was being charged with the current when the ore pulp was in a strong solution containing the same alkali metal ions as are combined with the mercury to form the said amalgam.

In the carrying out of my invention I prefer to use a mercury cathode of such exposed surface that I can conveniently get a current density of about 1.5 amperes per square inch of surface and I use as the electrolyte a solution of sodium hydroxid of about 25 to 30 per cent. strength. I desire it to be understood, however, that this percentage may be a little higher or a little lower without departing from the spirit and scope of my invention. The essential thing is that the solution must be sufficiently strong to protect the sodium or other alkali amalgam against rapid decomposition due to the action of water. The electrolyte containing the alkali thus in solution also contains therein the metalliferous ore which is caused to flow repeatedly and successively in contact with or against the surface of the amalgam in the manner already described or in any other suitable way. The platinum and other precious metals in the ore pulp which can form amalgams with or can be held by the mercury for longer or shorter periods of time are in the mercury in the usual way.

I claim 1. The method of extracting platinum and other precious metals from their ores which consists in forming a pulp consisting of the ores of said metals in a practically saturated solution of an alkali metal ion in combination with an ion of opposite character and causing the particles of said pulp to come in contact successively and repeatedly with the mercury cathode of an electric circuit.

2. The method of extracting and separating platinum and other precious metals from their ores which consists in forming a pulp comprising the ores of said metals and a practically saturated solution of an alkali metal ion in combination with an ion of opposite character, passing an electric current which consists in forming a practically saturated solution containing alkali metal ions, mixing the ores of said metals with the said solution to form a pulp, causing an electric current to flow through the said pulp and simultaneously agitating the latter to cause the particles thereof to flow and come in contact successively with a mercury cathode constituting a part of the circuit for the electric current.

4. The method of extracting and separating platinum and other precious metals which can form an amalgam with mercury from their ores, which consists in forming a pulp comprising the metalliferous ores in granular form and a practically saturated solution containing an alkali metal ion, confining the same in a receptacle in contact with a mercury cathode, causing an electric current to flow through a portion of the said pulp and simultaneously agitating the said pulp to cause the particles thereof to flow in contact with the said cathode, substantially as described.

5. The method of extracting platinum and other precious metals from their ores which consists in forming a pulp comprising an ore containing the said metals in granular form mixed with an electrolyte containing alkali metal ions in practically saturated solution, causing an electric current to flow between the anode and a mercury cathode situated within the said pulp, the said current being of sufficient strength to cause the formation of a metallic amalgam and the said solution being of a strength to protect the said amalgam against rapid decomposition from the action of the water upon the said alkali metal of the amalagam and" means for agitating the said pulp to cause the particles thereof to'flow in contact with the said cathode.

6. The method of extracting platinum and other precious metals from their ores which consists in forming a pulp comprising the ores of said metal in granular form mixed with a practically saturated solution of sodium hydroxid, said pulp being confined within a receptacle, causing an electric current to flow through the said pulp and a sodium-amalgam cathode situated so that the said pulp contacts therewith and agitating the said pulp to cause the particles thereof to flow in contact with the said cathode.

7. The method of extracting platinum and other precious metals from their ores which consists in forming a pulp comprising the ores of said metals in granular form mixed with a practically saturated solution of sodium hydroxid, causing a current of electricity to pass through a portion of the said pulp between the anode and the cathode of an electric circuit, said current being of a strength to effect the formation of a sodiumamalgam and the said sodium hydroxid solution being of a strength suihcient to retard the reaction of the sodium in said amalgam with Water to form sodium hydroxid and hydrogen and agitating the said pulp so as to cause the particles thereof to fiow successively in contact with the said cathode to thereby efi'ect extraction of all of the metal from the said ore and thereafter separating the said metal from the said pulp.

In testimony that I claim the foregoing as my invention, I have hereunto signed my name this second day of December, A. D. 1916.

SAML. S. SADTLER. 

